Background & aim: Sleep quality, alexithymia, and non-medication adherence are among the factors that contribute to the risk of developing or worsening coronary artery disease. Therefore, the aim of this study was to determine the effectiveness of cognitive emotion regulation on sleep quality, alexithymia and medication adherence of coronary artery patients. Methods: The quasi-experimental research design was pretest-posttest and follow-up with the control group. The statistical population of this study included all patients with coronary heart disease who referred to the specialized heart hospital in Urmia in 2022 who had referred to this center for medical services. The sample size consisted of 40 people from the mentioned community who were selected by available sampling method and randomly placed in two experimental and control groups. For the experimental group, cognitive emotion regulation intervention was implemented in 8 sessions of 50 minutes during four weeks, while the control group did not receive any training. The research instruments included the Pittsburgh Sleep Quality Inventory (1989), The Toronto Alexithymia Scale (1994) and the Morisky Medication Adherence Scale-8 (2008). The collected data were analyzed using the analysis of variance test with repeated measurements. Results: The results of the analysis of variance with repeated measurements showed that the intervention of cognitive regulation of emotion significantly improved sleep quality (F=76. 551, p<0. 01), difficulty in recognizing emotions (F=44. 102, p<0. 01), difficulty in describing feelings (F=30. 514, p<0. 01), externally oriented thinking (F=31. 981, p<0. 01) and non-medication adherence (F=43. 136, p<0. 01) in the sample It has been effective in cardiovascular patients. Conclusion: The results showed that the above emotional cognitive intervention has significantly improved the quality of sleep, ataxia, and adherence to treatment in the studied subjects, so the use of this intervention is suggested for cardiovascular patients.